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AERO PRECISION M4E1 Complete Multi-Caliber AR15 Lower Receiver w/ Magpul STR Stock - Black

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WARRIOR SYSTEMS WSM15 5.56 NATO / 223 Rem Billet AR15 Lower Receiver w/ Flared Mag Well | Black

TacFire AR-15 .223 / 5.56 Unassembled Upper Receiver Kit - 10"

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Next Level Armament - AR15 Lower Parts Kit - Mil-Spec - NLX662

AERO PRECISION M5 Complete Lower Receiver w/ MOE Grip - Black